Method of treating paper with a paraffin



No Drawing.

UNITED STATES}- METHOD OF TREATING PAPER WITH A PARAFFIN'.

To all whom it may concern:

Be it known that I, GEORGE W. MILES, citizen of the United States, and resident of Belmont, in the county of Middlesex and State of Massachusetts, have invented new and useful Improvements in Methods of Treating Paper with a Parafiin, of which the following is a specification.

My invention relates to the manufacture -of water-resistant paper, and consists of a method by which paper may be given any desired degree of paraffin finish within a wide range of proportionate incorporation of a parafiin in the paper. My invention is characterized by the application of a parafiin to the paper fiber in the form of an emulsion, which may be given any desired degree of dilution or extension, so as to produce any desireddegree of paraffin finish in the final product. The use of a parafiin emulsion enables the manufacturer to introduce the parafiin at any stage of the paper manufacture, from fiber in the beater to the fully formed paper web, and also eliminates the necessity for putting the paper through a'distinctly Separate parafiining process, such as is now practised.

A parafiin wax can be emulsified in water by a method which I have invented and which forms the subject matter of Letters Patent of the United States, No. 1,168,534, dated January 18, 1916. Briefly stated, this process of emulsifying a paraflin wax consists in melting the wax in mixture with a soap paste composed of a soap and an amount of water not materially exceeding a critical maximum proportion, to be ascertained empirically according to the character of the soap employed.

More particularly, as a specific example of the paraflin wax emulsifying process; take an ordinary soda-tallow soap, make a paste of the soap in three or four times its weight of water, and beat this paste with melted parafiin wax, maintaining the temperature at the boiling point of water.

In this instance, the proportion of parafiin Wax to soap (dry) may be ninety-five to five, though larger percentages of soap may be used. The quantity of water above specified is larger than the critical quantity required to efi'ect the emulsification of the parafiin Wax. By continued boiling, the excess of water is driven oil" until the critical proportion remains behind, when the paraflin wax goes into emulsion. The emulsion Specification of Letters Patent.

Application filed February 4. 1915. Serial No.

The precipitant not Patented Feb. 1, 11.921. 6,062.

thus prepared may be diluted or extended with water, as desired. t

Other waxes or waxy materials, such as fiarnaulliafiwgx, st'qarin,

e emu s1 e in t e ordinar wa and ma be mlxed with paraflin wax gmuls ibns, if de sired. paraflin wax emulsion, formed as above indlcated, can with advantage be introduced nto the beater with the'fiber. In order to correct any hardness of the water, t is deslrable to introduce rosin soap, or its equlvalent for such purposes, into the beater: before introducing the paraffin wax emulslon. When the .emulsion has been thoroughly ncorporated with the fiber, a suitable precipitant, such as alum, is added. only breaks up the wax emulsion, but also precipitates the size-such as rosln soap upon the fibers. This simultaneous PI'BCIPItatIOII deposits the wax part1cles with the size upon the fibers, whichthereafter carry both size and wax into the body of the paper web.

Other sizing materials, such as glue or starch, may be used, or may be mixed with the rosin s1ze.,

The characteristic of a true paraffin wax emulsion such as made by treating parafiin wax by the method above described, is that the paraffin exists in the emulsion in the form of very finely divided, suspended, solid particles of parafiin, each of which possesses the physical properties peculiar to a solid paraflim This condition is distinguished from one in which paraflin having been associated with other substances, such as oils, has become liquid or viscous, possesses a melting point considerably lower than that of parafiin in its essentially pure or natural condition, and is therefore no longer waxy or like paraffin in the true sense of the Word.

The finely divided paraflin is thus distributed through and incorporated with the fiber of which the paper is subsequently made. More or less parafiin can be thus incorporated with the fiber simply by variation of the proportions or strength of the paraflin wax emulsion introduced into the paper stock. For some purposes, distribution of the paraflin wax, in emulsion, among the paper fibers before these are actually aggregated to form the paper web, is to be preferred to the more superficial addition of a paraffin wax to the paper after the web is formed. By introducing the emulsion or Japan wax, may

into the beater, for example, each fiber becomes parafiin-treated and the parafiin is more thoroughly distributed through the body of the paper than it can be when the wax is a plied to the formed web. Calendering o? a paper, the individual fibers of which have received a paraflin treatment, will bring out the characteristic superficial waxy finish.

In many cases, however, it will suit the requirements of the paper manufacturer to apply a parafiin wax to the formed paper web, even after the wax has been incorporated in the structure by the specific mode above described. A parafiin wax emulsion may be brushed or sprayed on to 'the paper web, either when the latter is still wet, or after it has been dried. If'desired, suitable sizing material, such as casein, glue, or starch, may advantageously be mixed with the paraflin wax emulsion. Or, the paper may be passed through a bath of the emulsion. Unlike the method of applying melted parafiin, either by brushing or immersion, the emulsion method is susceptible of accurate control. "The quantity of wax per pound of paper can be readily determined, andwidely varied, simply by variations in the dilution of the emulsion, or of the rate at which it is brushed or sprayed, or of the rate at which the paper web is passed through it, or of the length of paper immersed in a bath of the emulsion. Calendering of the paper, after a paraflin wax coating by emulsion, will complete the desired finish. Or, if the paper is simply dried, it will possess Water-resistant qualities and a relatively dull finish.

I claim:

1. The method of producing water-resistant paper, which consists in applying to the fibrous material of the paper an emulsion of paraffin wax, depositing upon the fibrous material, from said emulsion, minute solid articles of the said wax.

2. he method of producing water-resistant paper, which consists in applying tothe fibrous material of the paper an emulsion of paraflin wax, depositing upon the fibrous.

material of the paper, at-a stage in advance of the formation of the paper web, an emulsion of paraffin wax, depositing upon the fibrous material from said emulsion, minute solid particles of the said wax.

4. The method of treating paper stock for the production of water resistant paper,

which consists in introducing an emulsion of parafiin wax into the fibrous material while in the beater, incorporating solid particles of the said wax with said fibrous material and eventually into the paper web.

5. The method of treating paper stock, which consists in introducing an emulsion of solid particles of unmodified paraffin wax with a size into the water vehicle in which the paper fiber is distributed at a stage in the progress of the fiber in advance of formation of the paper web, thereafter precipitating the size on the fiber with the parafiin wax, thus incorporating the paraflin wall; with the fiber and finally into the paper we Signed by me at Boston, l\lassachusetts, this thirtieth day of January, 1915.

GEORGE W. MILES.

\Vitnesses JOSEPHINE H. RYAN, RICHARD W. HALL. 

